Los Angeles County public health officials backtracked Tuesday on their statements last week that at least 16 unpublicized cases of HIV in adult film performers had been reported to them since 2004.

Despite their release of data describing the cases as “adult film performers,” the county’s top health official acknowledged that the agency does not know whether any of those people were actively working as porn performers at the time of their positive test.

Health officials also corrected upward, from 16 to 18, the total number of new cases reported by the Adult Industry Medical Foundation, a San Fernando Valley-based clinic that serves the porn industry, since a 2004 HIV outbreak and the revelation last week that a female porn performer had tested HIV positive.

County public health officials said they had mislabeled all reports from the AIM clinic as adult performers when, in fact, information about their occupation is unclear. Although the clinic was created primarily to serve the porn industry, it serves other clients.

“We have no information on these individuals,” Dr. Jonathan Fielding, the county’s health officer. “All we have is the number from AIM.”

Sharon Mitchell, the clinic’s co-founder, said this week that none of the HIV cases cited by the county involved active performers.

“Here’s the bottom line: We’re an HIV testing center,” Mitchell said. “We don’t just test the adult entertainment industry. We have a lot of people who come who want testing from the general public.”

Mitchell said all previously unpublicized cases involved either a non-performer or an aspiring actor or actress who tested positive, then dropped out of the business.

She said that the female actress who tested positive for HIV at their clinic earlier this month remains the only case detected in a working performer since 2004. At that time, a male porn star and three actresses with whom he had performed all tested HIV positive. An unrelated transsexual performer also tested HIV positive the same year. The cases shut down production in Southern California’s multibillion-dollar porn industry for a month.

Fielding said Tuesday that the county did little investigation of any of the post-2004 cases and have few details about the individuals, their partners or how they may have been infected. Mitchell, whose clinic settled a breach of privacy lawsuit brought by Darren James, the porn star at the center of the 2004 outbreak, said she could not release names or information because of privacy laws.